JP2001137744A - Rotational atomization type coating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely and efficiently clean a rotational atomization head by a simple constitution. SOLUTION: An apparatus body 12 is provided with a shaving air jetting hole 58 for jetting shaving air toward the outer peripheral face 20b of a rotational atomization head 20, a shaving air passage 52 for feeding the shaving air into the shaving air jetting hole 58 and a cleaning valve 64 being freely connectable with the shaving air passage 52 and for jetting a cleaning liquid toward the outer peripheral face 20b of the shaving air jetting hole 58.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary atomizing type coating apparatus having a rotary atomizing head capable of discharging a paint to a work, and an apparatus body for rotatably mounting the rotary atomizing head. .

[0002]

2. Description of the Related Art In general, a coating apparatus for applying a high voltage to a coating material (liquid coating material) to apply an electrostatic coating to an object to be coated such as an automobile body is employed. For example, there is known a rotary atomizing type coating apparatus which discharges paint by the action of centrifugal force from the leading edge of the rotary atomizing head under the rotating action of the rotary atomizing head.

[0003] In this type of rotary atomizing type coating apparatus, since the coating easily adheres to the rotary atomizing head itself, a cleaning liquid path is usually provided in the main body of the apparatus close to the coating path. For example, when the color of the paint is changed, a cleaning liquid is supplied to the cleaning liquid path while rotating the rotary atomizing head, thereby performing an operation of cleaning the rotary atomizing head.

However, as described above, the cleaning liquid supplied from the cleaning liquid path is led out to the inner side of the rotary atomizing head to clean the inner surface of the rotary atomizing head. For this reason, it is not possible to wash the paint adhering to the outer periphery of the rotary atomizing head, especially the outer peripheral end edge which is the paint discharge end. As a result, there is a problem in that the paint that has adhered to the rotary atomizing head and solidified adheres to the object to be coated, or mixes with the color-changed paint and mixes, resulting in defective painting.

Therefore, for example, Japanese Patent Application Laid-Open No. Hei 6-218301
As disclosed in Japanese Patent Application Laid-Open Publication No. H11-163, there has been proposed to prevent paint stain by making the air flow on the outer peripheral surface of the rotary atomizing head smoothly flow in one direction. Specifically, as shown in FIG. 3, a rotary atomizing head 4 is fixed to a tip of a rotating shaft 3 rotatable via an air motor 2 built in the apparatus main body 1. The outer peripheral surface of the rotary atomizing head 4 is formed with an expanded surface 4a having an angle α (15 ° ≦ α ≦ 25 °) with respect to the axis.

Therefore, the shaping air SA and the exhaust air EA derived from the shaping ring 5 provided on the apparatus main body 1 are discharged on the expanding surface 4a.
It flows smoothly toward b. Thereby, the generation of entrained air is prevented, and the paint is prevented from adhering to the expanding surface 4a.

[0007]

However, in the above-mentioned prior art, it is intended to prevent the paint from adhering to the rotary atomizing head 4 by using the shaping air SA and the exhaust air EA. The adhesion of the paint cannot be reliably avoided over a long period of time. For this reason, it has been pointed out that the rotary atomizing head 4 needs to be periodically cleaned (cleaned), and the efficiency of the entire coating operation cannot be improved. In addition, if the rotary atomizing head 4 is stained at an early stage, there is a possibility that defective coating due to color mixing or the like may be caused.

The present invention has been made to solve this kind of problem, and an object of the present invention is to provide a rotary atomizing type coating apparatus capable of reliably and efficiently cleaning a rotary atomizing head with a simple structure. And

[0009]

In a rotary atomizing type coating apparatus according to the present invention, a rotary atomizing head capable of discharging a paint to a work is mounted on a main body of the apparatus, which faces the outer periphery of the rotary atomizing head. A shaping air injection port for injecting the shaping air, and a cleaning liquid for injecting a cleaning liquid from the shaping air injection port toward the rotary atomizing head in a shaping air path communicating with the shaping air injection port. The supply means is freely connectable.

Therefore, the cleaning liquid such as thinner can be discharged from the shaping air injection port toward the outer periphery of the rotary atomizing head only by connecting the cleaning liquid supply means to the shaping air path. As a result, the cleaning operation of the outer peripheral surface of the rotary atomizing head, particularly the outer peripheral edge which is the paint discharge end, can be reliably and efficiently performed with a simple configuration, and the efficiency of the entire coating operation can be easily increased. .

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic internal structural explanatory view of a rotary atomizing type coating apparatus 10 according to an embodiment of the present invention.

The coating apparatus 10 has an apparatus main body 12, in which an air motor 14 is disposed, and a cylindrical rotary shaft 18 is integrally formed with an air turbine 16 constituting the air motor 14. And a rotary atomizing head 20 is fixed to the tip of the rotary shaft 18. In the center of the apparatus main body 12, a pipe member 22 is disposed in the rotary shaft 18, and a paint path 24 and a cleaning liquid path 26 are formed in the pipe member 22. The tips of the paint path 24 and the cleaning liquid path 26 are open to the outside from the center side of the rotary atomizing head 20.

The paint path 24 is opened under the action of a paint valve 28 so that a predetermined paint can be discharged onto a work (not shown). The paint path 24 includes a discharge port 24a for discharging paint, a valve seat 30 provided inside the discharge port 24a, one end communicating with the valve seat 30, and the other end forming a paint valve 28. A housing portion 34 communicating with a casing portion 32 to be described later, and a paint introduction portion 36 communicating with the housing portion 34 at an angle with respect to the other end side of the housing portion 34 are provided.

The paint valve 28 includes a cylinder tube 40 fixed to the inside of the apparatus main body 12, and a piston 42 which is movable in the axial direction (direction of arrow A) by fluid pressure, for example, pneumatic pressure. Is arranged. A rod portion 44 extends in the axial direction from the end of the piston 42, and a valve stem 4
6 are provided. Seal ring 4 on the peripheral surface of rod portion 44
The seal ring 48 is slidable along the inner peripheral surface 32 a of the casing 32.

The valve stem 46 is connected to the valve seat 30 of the paint path 24.
, The paint path 24 can be closed freely. The housing portion 34 is provided with a paint introduction chamber 49 at an end opposite to the valve seat portion 30 so as to have a larger diameter.
At the position corresponding to the paint introduction chamber 49, there is formed a tapered portion 50 whose diameter decreases toward the valve seat portion 30 side.

The cleaning liquid path 26 has a cleaning liquid discharge port 26a for discharging the cleaning liquid on the inner surface 20a of the rotary atomizing head 20, and a shaping air path 52 in the apparatus main body 12.
Connected to. As shown in FIG. 2, a plurality of air passages 54 communicate with the tip end of the shaping air passage 52, and the tip end of the air passage 54 communicates with the shaping air injection port 58 through the opening 56. The shaping air injection port 58 is open toward the outer peripheral surface 20 b of the rotary atomizing head 20, particularly toward the outer peripheral front edge 20 c.

As shown in FIG. 1, the cleaning liquid path 26 includes:
The switching valve mechanism 60 is connected. The switching valve mechanism 60 includes an air valve 62 for supplying air including shaping air, and a cleaning valve (cleaning liquid supply means) 64 for supplying a cleaning liquid containing water and thinner.

The apparatus main body 12 is provided with a backup air path 66, and an air path 68 communicates with a tip side of the backup air path 66. The tip of the air path 68 is opened to the rotary atomizing head 20 side. I have. The apparatus main body 12 accommodates a high-voltage applying unit (not shown) for charging the paint discharged from the rotary atomizing head 20 with static electricity.

The operation of the coating apparatus 10 thus configured will be described below.

The paint is supplied to the paint path 24 from a paint supply source (not shown), and the valve stem 4 constituting the paint valve 28 is provided.
The discharge of the paint is stopped by the seat 6 being seated on the valve seat 30. Then, the rotary atomizing head 20 is rotated at high speed through the air turbine 16 under the action of the air motor 14, and the paint valve 28 is driven to move the valve stem 46 inward (in the direction of arrow A1). The tip of the valve stem 46 is separated from the valve seat 30. Therefore, the paint supplied to the paint path 24 is discharged from the discharge port 24a to the rotary atomizing head 20, and a high voltage is applied through a high voltage applying unit (not shown).

At this time, shaping air is supplied to the shaping air path 52 under the action of the air valve 62, and the shaping air is supplied from the air passage 54 to the outer peripheral surface 20 b of the rotary atomizing head 20 via the shaping air injection port 58. While being injected, the backup air supplied to the backup air path 66 flows from the air passage 68 to the rotary atomizing head 2.
0 to the back side. Thereby, the paint charged with static electricity is formed into a predetermined spray pattern in an atomized state,
A desired electrostatic painting operation is performed on a work (not shown).

Next, after the predetermined number of workpieces have been coated, the rotary atomizing head 20 is washed. That is, the cleaning valve 64 constituting the switching valve mechanism 60 is connected to the cleaning liquid path 26 and the shaping air path 52, and the cleaning liquid is supplied to the cleaning liquid path 26 and the shaping air path 52. Therefore, the cleaning liquid path 2
The cleaning liquid is discharged to the inner surface 20a of the rotary atomizing head 20 from the cleaning liquid discharge port 26a provided on the distal end side of the nozzle 6, and the rotary mist is formed through the shaping air injection port 58 from the air passage 54 communicating with the shaping air path 52. The cleaning liquid is discharged to the outer peripheral surface 20b of the head 20 (see FIG. 2).

As a result, in the present embodiment, the inner surface 20a and the outer peripheral surface 20b of the rotary atomizing head 20 are cleaned at the same time, and the effect of greatly improving the cleaning efficiency of the rotary atomizing head 20 is obtained. Can be In addition, the outer peripheral tip 20c, which is the paint discharge end of the rotary atomizing head 20, can be reliably cleaned through the cleaning liquid discharged from the shaping air injection port 58, and the solidified unnecessary paint adheres to the surface to be coated. And effectively perform high-quality painting work.

In this embodiment, the cleaning liquid path 26 is connected to the shaping air path 52, and the switching valve mechanism 60 is connected to the cleaning liquid path 26.
Separate cleaning liquid supply means may be connected to the cleaning liquid path 26 and the shaping air path 52, and the cleaning operation of the inner surface 20a and the outer peripheral surface 20b of the rotary atomizing head 20 may be independently performed at a suitable timing. Further, by performing the cleaning operation simultaneously with the discharge of the cleaning liquid during the color change cleaning, it is possible to effectively prevent the paint of the previous color from being mixed with the paint of the color change.

[0025]

According to the rotary atomizing type coating apparatus according to the present invention,
When the cleaning liquid supply means is connected to the shaping air supply path, the cleaning liquid such as thinner is discharged from the shaping air injection port toward the outer periphery of the rotary atomizing head. The cleaning operation of the outer peripheral front edge, which is the discharge end, is performed reliably and efficiently with a simple configuration. Thereby, the efficiency of the entire coating operation of the rotary atomizing head can be easily improved, and coating defects can be effectively prevented to achieve high-quality coating.

[Brief description of the drawings]

FIG. 1 is a schematic internal configuration explanatory view of a coating apparatus according to an embodiment of the present invention.

FIG. 2 is an explanatory view of a cleaning operation of a rotary atomizing head constituting the coating apparatus.

FIG. 3 is a partially sectional explanatory view of a coating apparatus according to a conventional technique.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Coating device 12 ... Device main body 14 ... Air motor 16 ... Air turbine 18 ... Rotating shaft 20 ... Rotary atomization head 20a ... Inner surface 20b ... Outer peripheral surface 20c ... Outer peripheral edge 24 ... Paint path 24a ... Discharge port 26 ... Cleaning liquid path 26a ... Cleaning liquid discharge port 28 ... Paint valve 30 ... Valve seat part 32 ... Casing part 32a ... Inner peripheral surface 34 ... Accommodation part 36 ... Paint introduction part 46 ... Valve rod part 50 ... Tapered part 52 ... Shaping air path 54 ... Air path 58 ... Shaping air injection port 60 ... Switching valve mechanism 62 ... Air valve 64 ... Washing valve

Claims (1)

[Claims] 1. A rotary atomizing type coating apparatus comprising: a rotary atomizing head capable of discharging a paint to a workpiece; and a device main body on which the rotary atomizing head is rotatably mounted. A shaping air injection port for injecting shaping air toward the outer periphery of the rotary atomizing head, a shaping air path for supplying shaping air to the shaping air injection port, and a shaping air path that is freely connectable to the shaping air path. A cleaning liquid supply means for injecting a cleaning liquid from a shaping air injection port toward an outer periphery of the rotary atomizing head.